This invention relates generally to bins and other bulk material containers and more particularly to a closure assembly for a top opening in a bin having improved seal and lid retaining features.
Closure assemblies, particularly various configurations of lids, are in common use with many tyes of containers and are an essential component in many sealed containers. The object of this invention is to provide an improved closure assembly for a portable bulk material handling bin that provides a positive seal and positive retainers to maintain the lid in a sealed configuration in the opening of the bin.
The closure assembly according to the present invention is designed for application in a bin having a top wall which has a tubular wall portion forming a generally circular passage through the top wall. The closure assembly comprises a generally circular lid having a cylindrical rim portion which fits within the passage.
The rim portion has an outwardly open retaining groove extending circumferentially around the rim portion. Disposed in this groove is an O-ring seal which has a cross-sectional diameter greater than the depth of the groove so that a portion of the O-ring seal projects beyond the edge of the rim. When the lid is positioned within the circular passage in the top wall of the bin this O-ring seal is compressed elastically to provide a positive seal between the lid and the passage walls. In addition, there are coacting means on the lid member and on the top wall for retaining the lid in position enclosing the passage with the cylindrical rim portion extending downwardly into the passage, the O-ring seal being compressed between the rim portion and the tubular wall portion of the top wall.
The coacting means on the lid and the top wall comprises a lid cowling having a ring shaped base portion fixed symmetrically to the lid and having equally spaced hook shaped retainers projecting outwardly from the base portion and beyond the rim portion of the lid. The tubular wall portion of the top wall forming the passage has a like number of outwardly directed tabs which project away from the passage. The retainers engage the outwardly directed tabs when the lid is positioned with the rim portion extending downwardly into the passage to close off the passage and the lid is rotated. Rotating the lid engages the retainers with the tabs thereby securing the lid to the bin.
The closure assembly of the present invention including the O-ring seal disposed groove in the cylindrical portion of the lid has several advantages. First, in a large bin, having the seal member on the lid allows simplified maintenance of the seal. The seal can be conveniently removed, replaced, or cleaned without having to disturb the bin itself. Second, having the seal on the lid allows the tubular passage in the top portion of the bin to be smooth thus preventing accumulation of bulk material on the wall of the passage during filling of the bin. Third, the interlocking tabs and retainers are simply formed from sheet metal thus simplifying the construction of the closure assembly thereby minimizing cost.
Further objects, features, and advantages of this invention will become apparent from a consideration of the following description and the independent claims in connection with the accompanying drawing.